refactor(deployment): Remove WireGuard VPN dependency and restore public service access

Remove WireGuard integration from production deployment to simplify infrastructure:
- Remove docker-compose-direct-access.yml (VPN-bound services)
- Remove VPN-only middlewares from Grafana, Prometheus, Portainer
- Remove WireGuard middleware definitions from Traefik
- Remove WireGuard IPs (10.8.0.0/24) from Traefik forwarded headers

All monitoring services now publicly accessible via subdomains:
- grafana.michaelschiemer.de (with Grafana native auth)
- prometheus.michaelschiemer.de (with Basic Auth)
- portainer.michaelschiemer.de (with Portainer native auth)

All services use Let's Encrypt SSL certificates via Traefik.

tests/debug/test-homepage-qrcode.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/../../vendor/autoload.php';
+
+use App\Framework\QrCode\QrCodeGenerator;
+use App\Framework\QrCode\QrCodeRenderer;
+use App\Framework\QrCode\ValueObjects\ErrorCorrectionLevel;
+use App\Framework\QrCode\ValueObjects\QrCodeStyle;
+
+$testUrl = 'https://localhost/';
+
+echo "Testing QR Code for: {$testUrl}\n\n";
+
+try {
+    $renderer = new QrCodeRenderer();
+    $generator = new QrCodeGenerator($renderer);
+    
+    // Generate with default style
+    $dataUri = $generator->generateDataUri($testUrl);
+    
+    echo "✅ QR Code generated successfully\n";
+    echo "Data URI length: " . strlen($dataUri) . " characters\n\n";
+    
+    // Generate with larger style for better scanning
+    $largeStyle = QrCodeStyle::large();
+    $largeSvg = $generator->generateSvg($testUrl, ErrorCorrectionLevel::M, null);
+    $largeDataUri = $renderer->toDataUrl(
+        \App\Framework\QrCode\QrCodeGenerator::generate($testUrl),
+        $largeStyle
+    );
+    
+    echo "✅ Large QR Code generated\n";
+    echo "Large Data URI length: " . strlen($largeDataUri) . " characters\n\n";
+    
+    // Save SVG for inspection
+    $svgFile = __DIR__ . '/homepage-qrcode.svg';
+    file_put_contents($svgFile, $largeSvg);
+    echo "SVG saved to: {$svgFile}\n\n";
+    
+    echo "Recommendations:\n";
+    echo "1. Use larger module size (20px instead of 10px)\n";
+    echo "2. Ensure quiet zone is 4 modules (already default)\n";
+    echo "3. Test with multiple QR code scanner apps\n";
+    echo "4. Check if SVG is rendering correctly in browser\n";
+    
+} catch (\Exception $e) {
+    echo "ERROR: " . $e->getMessage() . "\n";
+    echo "Trace:\n" . $e->getTraceAsString() . "\n";
+}
+
+